Sewell was raised in Selma. She is the daughter of Andrew A. Sewell, a former athletic coach, and Nancy Gardner Sewell, a former City Councilwoman and retired librarian of Selma. Her mother was the first black woman elected to the Selma City Council.[citation needed] Both parents held careers in the Selma public school system.

Terrycina Sewell became the first black valedictorian of Selma High School. Her mother's family had offered its homestead to travelers coming for the 1965 Selma to Montgomery marches. Sewell spent her childhood summers in Lowndes County, Alabama with her maternal grandparents. Her grandfather, a Primitive Baptist minister and a farmer, instilled in her a love for the land, an appreciation of hard work, and the importance of her faith. Her grandfather and the members of Beulah Primitive Baptist Church gave her a deep understanding of the Black Belt Region of Alabama and its people.

Sewell graduated with honors from Princeton University and received a scholarship from U.S. News and World Report, among others. A lifelong Democrat, during the summers while in college, she worked on Capitol Hill for 7th congressional district congressman Richard Shelby, as well as for Senator Howell Heflin. She was a leader on the college campus, serving in various roles including class vice-president, class representative to the Student Union, and spearheading the admission office’s effort to set up a Minority Student Recruitment office to recruit more minority students to attend the university.[5]

Upon graduation from college, Sewell was featured on NBC’s Today Show as one of the “Top Collegian Women.” She was chosen as one of the “Top Ten College Women in America” by Glamour Magazine. She received the Afro-American Studies Thesis Prize for her senior thesis, Black Women in Politics: Our Time Has Come, which featured a personal interview with Shirley Chisholm, the first black U.S. Congresswoman.[6] Sewell continued her education, receiving a Masters degree with first-class Honours from Oxford University. At the age of 25, she published her Masters’ thesis on the election of the first black members of British parliament as a book titled, Black Tribunes: Race and Representation in British Politics.[7]

After graduation, Sewell served as a judicial law clerk in Birmingham, Alabama to the Chief Judge U. W. Clemon,[9] United States District Court (AL-ND), who was the first black federal judge appointed in Alabama.

Sewell began her legal career in 1994 at the Wall Street law firm of Davis Polk & Wardwell. A securities lawyer for more than a decade, she gained experience in finance and the capital markets. Sewell provided free legal services to the homeless, mentoring girls of color in NYC high schools through the program Dreams into Action and serving on the Alumni Advisory Board of Sponsors of Educational Opportunity (SEO), a not-for-profit organization providing education, leadership training and Wall Street internships to students of color. Through her involvement with SEO, she served as the co-chair of the Community Assistance Fund, which provided $300,000,000 of aid and assistance to organizations serving communities of color affected by the events of September 11, 2001.

After four-term Democratic incumbent Artur Davis gave up the seat to run for governor, Sewell entered the Democratic primary—the real contest in this majority Democratic, majority-black district. She finished first in the four-way primary with 36.8 percent of the vote.[10] In the runoff, she defeated Jefferson County commissioner Sheila Smoot with 55 percent of the vote.[11][12]

In the general election, Sewell trounced Republican challenger Don Chamberlain, taking 72.4 percent of the vote to become the first black woman elected to Congress from Alabama. The 7th is so strongly Democratic that Sewell essentially clinched her seat by winning the primary.[13]

Since being elected, Sewell has voted with her party 91% of the time, and she has been noted as a strong supporter of President Obama's policies.[16][17] Sewell has established herself as a loyal Democrat and liberal with a focus on job creation.[18] Sewell is a member of the Congressional Black Caucus.

Taxation

Sewell supported President Obama's plan to extend tax cuts for low- and middle-income Americans, but declined to discuss her stance on taxation for high-income Americans.[16] In response to Obama's Framework for Business Tax Reform, Sewell said: "I applaud the President for outlining a bold framework for reforming the U.S. business tax system."[19]

In 2012 Terri Sewell criticized Republican Presidential nominee Mitt Romney's tax returns and effective tax rates, saying "… It should be about shared responsibility. I think that something is fundamentally wrong if a person of his great wealth is only paying 13.9 percent effective tax rate and most of Americans are paying 28, 30 percent and they make far less.”[20]

Foreign policy

Sewell supported Obama's decisions regarding Afghanistan, citing "trust" for his policies.[16] She was part of a bi-partisan delegation to accompany Nancy Pelosi on a 2-day trip to Afghanistan in May 2012. While there, they spent time "with American service-members and meeting local officials to discuss security and women’s issues."[21]

H.R. 1730, a bill to create small business start-up savings accounts, with annual contributions up to $10,000, to pay for trade and business expenses, and to be taxed similarly to Individual retirement accounts, introduced May 4, 2011, reintroduced in the 113th Congress as H.R. 1323

H.R. 1324, a bill to allow for a business-related tax credit equal to 50% of wages (up to $2,000) paid to an apprenticeship employee during an apprenticeship period and 40% of wages (up to $6,000) paid to such an employee during a post-apprenticeship period, introduced March 21, 2013

Terri Sewell served as co-chair of the Women’s Fund “Voices Against Violence” inaugural campaign, which promoted women helping women to overcome domestic violence. The campaign raised more than $70,000 in four months to fight domestic violence in Birmingham, providing funds to establish the first Domestic Violence Court in Birmingham Municipal Court.[23] Sewell led the effort to have Teach for America select Alabama’s Black Belt region as a new site in 2010.

Sewell was listed in the magazine Alabama Super Lawyers[7] for 2008 and 2009. She was honored with the 2007 Minority Business “Rising Star” award by the Birmingham Business Journal (BBJ).[23] She was selected by the BBJ as one of the “Top Birmingham Women” in 2005. She was a member of the class of 2006-2007 Leadership Birmingham, and a member of the YWCA’s Women Leadership MOMENTUM class of 2007-2008. She is currently a member of the class of 2008-2009 Leadership Alabama.

Sewell is a lifetime member of Brown Chapel AME Church in Selma. She currently worships at Sixth Avenue Baptist Church in Birmingham. She was selected to participate on the panel, "From Lincoln to Obama," for the Congressional Black Caucus' Annual Legislative Forum to discuss Southern politics.